Transmissions, such as vehicle transmissions, have one or more gear meshes that selectively transfer torque from an input shaft to an output shaft of the transmission. The gear meshes are lubricated during transmission operation, and transmission fluid is commonly used as the lubricant. The gear meshes and the lubricating fluid are contained within a transmission case or housing, and a sump may be provided at the bottom of the transmission case to collect the fluid and act as a reservoir. Transmissions may be provided with a sight glass visible from outside the transmission housing where the fluid level within the transmission may be visually checked when the transmission and vehicle are at rest, for example, with the engine not running. Alternatively, the fluid level in the transmission may be manually checked by inserting a dip stick, or the like, into the fluid fill port of the transmission housing to check the fluid level when the transmission and the vehicle are at rest.